This R13 application seeks partial support for the satellite meeting Immunosenescence: Hot Topics and Interventions, organized in conjunction with the European Congress of Immunology (ECI) which will be held in Vienna (Austria), September 6th to September 9th, 2015. This satellite meeting will take place in Vienna, September 5th and 6th 2015 and will bring together scientists not only from Europe, but from all over the world. The previous satellite meeting, entitled Aging and the Immune System, organized in conjunction with the 15th International Congress of Immunology (Milan, Italy, August 2013), brought together an internationally recognized group of 124 established scientists and young investigators. This meeting was unique as it was one of the largest meetings dedicated to the field of the aging immune system. Previously, a satellite meeting on the same topic was organized in Paris, France, September 2006 in conjunction with the 1st European Congress of Immunology. This satellite meeting was also attended by a large number of internationally recognized experts, but for the following 7 years nothing similar was organized. After these two successful satellite meetings on immunosenescence, we hope that these events will take place on a regular schedule. Following the great success of the previous satellites, we are requesting financial support in this proposal for the next satellite in Vienna, in particular fr the participation of speakers from the United States. The planned conference will highlight the aspect of aging in the context of immunological research with a special focus on mucosal immunity, the impact of metabolism on the immune system, the interplay of diseases and the immune system as well as recent developments in the field of vaccination and immune reconstitution. It will also provide an excellent venue to strengthen already existing collaborations and to create new opportunities for cooperation between European and American researchers in the field of immunosenescence. This meeting will also aim to attract to this field new investigators and young researchers attending the main congress. Based on previous attendance, we expect up to 200 participants. The objectives are to summarize recent progress in basic research on the immunology of aging, to trigger discussion and translation of key recent findings, to optimize interactions and networking among USA and international scientists. We will also have a dedicated issue in one of the journals of the field, as it was for the satellite i Paris (Exp. Gerontol. 42 (5), 2007) and in Milan (Exp. Gerontol. 54, 2014). The venue is one of the largest conference venues in Europe.